It is a recognized problem that children will often reach for and play with containers which contain medicines or other substances which, if improperly taken, can result in serious and harmful health reactions, and in some instances, even death. As a result many forms of child resistant containers have been designed to prevent children from being able to easily open the containers. This, however, has had the undesirable effect that the aged and infirm have also been unable to open the very same containers to reach and take needed medications, or the like.
U.S. Pat. No. 4,144,983 to Pauls et al. relates to a child-resistant closure assembly having a cap which includes a plurality of detents. When the cap is screwed onto the container in a tightening direction, the cap detents engage a cooperating surface of a detent on the container, thereby allowing the cap detents to move past and the cap to be tightly secured to the container. When the cap is screwed off of the container in a loosening direction, a second surface of the detent on the container engages with a detent on the cap to lock the cap in place. To remove the cap a flexible release member carrying the detent on the container is pushed in one direction causing the detent to slide inside of the detents of the cap in the same direction. As the detent slides to the inside this could cause the problem of a jamming of the cap such that it could not be removed either because of expansion of the detents due to temperature increase in the environment or due to breakage of the detent.
U.S. Pat. No. 5,413,233 to Hall relates to a child resistant bottle having a resiliently deformable vertical beam with a locking surface, and a push tab thereon attached at a neck of the bottle. A closure has a ramped tooth projecting inward from an inner surface of the closure, such that when the closure is screwed onto the bottle, the tooth engages the locking surface of the beam in such a manner to prevent any unscrewing of the closure. In order to unscrew the closure from the bottle, the push tab must be manually depressed toward the bottle into a recess thereby removing the locking surface from the tooth on the closure. Again the problem exists that the tooth and the locking surface of the beam may become jammed as dirt or other debris may get caught in the recess in which the vertical beam is to be depressed thus preventing the beam from being depressed enough to disengage the locking surface from the tooth of the closure.
U.S. Pat. No. 5,562,218 to Hamilton et al. relates to a child resistant attachment for containers. A two-piece closure is screwed or snapped onto a container. To open the two-piece closure a spring-like pushtab on one piece containing a vertical extension which engages an interlocking pawl on the second piece is manually depressed. This activation causes the pushtab to disengage from the pawl so that the second piece can be unscrewed from the first piece. Once again, however, the problem exists that the two-piece closure may become jammed if debris lodge in a channel between the pushtab and the first piece to which it is attached, thereby preventing the pushtab from being able to be manually depressed.